CHLAMYDOSELACHUS ANGUINEUS. 43 
the Carboniferous and earlier. The excellent work done by James -W. 
Davis, by L. Déderlein, by Fritsch, and by a number of others, in the elu- 
cidation of the Pleuracanthidae has finally disposed of as non-existent the 
asserted affinities of Chlamydoselachus with Cope’s Didymodus, 1884, that 
is, with Pleuracanthus of Agassiz, 1857. As now separated from the spine- 
bearing fish-like Pleuracanths, Xenacanths, with which it should never have 
been placed, the first suggestion, in 1884, regarding the allies of Chlamy- 
doselachus is seen to retain its pertinence ; the affinities are to be looked 
for away back among the Cladodonts, “ probably earlier than the Carbon- 
iferous.” The idea that the Cladodonts were distinct from the Diplodonts, 
of the Xenacanthini, the Pleuracanthide, is well supported by the fossil 
Cladodont restored by Dean, 1894, under the name “ Cladoselache”’ (see 
“Fishes, Living and Fossil,” 1895, p. 79, fig. 86), from the Cleveland 
Shales of the Ohio Waverley (Lower Carbon). This form evidently was 
a true shark with Cladodont dentition and no dorsal spines; it has no 
close resemblances to Chlamydoselachus, yet it is sufficiently near to 
lend support to the theory that the ancestors of the latter had separated 
from the Diplodonts, the Pleuracanths, and Teleosts at a much earlier 
date, and to justify search for a Cladodont without dorsal spines, with 
more than five gill openings, with longer dorsal and anal fins, and with a 
tail somewhat nearly diphycercal, from which to trace the descent of the 
Chlamydoselachidee. 
The name originally applied to the genus was Chlamydoselachus, from 
xXAapvs and oédayos; Giinther’s change to Chlamydoselache is not to be 
countenanced, oehayyn being the plural form. Similar criticism is to be 
applied to Selache of Cuvier, 1817 (= Cetorhinus Blainville, 1816), and to 
Cladoselache of Dean, 1895, generic names which are better written 
Selachus and Cladoselachus. 
To remark upon one more of the numerous entries in a complete bibli- 
ography of the genus it may be pointed out that the diagnoses and descrip- 
tions occupying pages 22, 23, and 24 of the “Oceanic Ichthyology” by 
George Brown Goode and Tarleton H. Bean, 1896, are transcribed word for 
word, without quotation marks, but with changed punctuation, from the 
article, “ An Extraordinary Shark,” in vol. XVI, 1884, of the Proceedings 
of the Essex Institute. It is indeed gratifying to know that the article was 
so highly appreciated as to demand an expenditure of so much energy as 
was necessary in making all the changes, yet it is greatly to be regretted 
fo) fo} ? 5 vi fo) 
